Board machine



Sept. 19, 1933. J. EDGE 1,927,360

BOARD MACHINE Original Filed Dec. '24, 1928 Patmted Sept. 19, 1933UNITED STATES PATENT OFFICE BOARD MACHINE Jacob Edge, Downingtown, Pa.,assignor to Downingtown ,Manufacturing Company, Downingtown, Pa., acorporation of Pennsylvania 26 Claims.

The present invention relates to machines for the continuous productionof fiber boards, particularly fiber boards of substantial thickness, sayfrom one-half to one inch when dry, such as may, for instance, beutilized for building, insulating, or other purposes.

Many types of boards fabricated wholly or in large part of fibrousmaterials have heretofore been designed or suggested and numerousmachines for the production of such boardsactually built and operated.For the most part, however, such machines have been of the rotarycylinder type, that is, have involved the use of two cylinders disposedto rotate about parallel axes, the fibrous material being deposited intwo layers from the pulp stock on the cylindrical surfaces of themachines, such layers being pressed to gether by the cylinders and theresultant composite board removed by a doctor. Certain of such machineshave been of the suction type, the liquid of the pulp stock beingwithdrawn through the foraminous surface by suction. It has also beensuggested that boards may be formed on Fourdrinier machines, having flatforming wires, each such forming wire having a suction box beneath thesame to facilitate movement of liquid therethrough and the deposition ofthe fiber thereon.

Board forming machines of the two cylinder type have certain inherentdisadavantages which cannot be overcome. Thus, such a machine tends toproduce a laminated board which, after having been compressed and.dried, tends to split along its neutral axis or plane of bonding of thetwo component layers of which it is composed. Machines necessarilyemploying suction to aid in the deposition of the fibers on the formingsurface also have certain-inherent defects. For instance, where suctionis employed to draw the pulp liquid more rapidly through the formingmember, it is found that the fiow of this liquid does not occur at thesame rate over the forming surface, and, as a result, a board ofnon-uniform thickness results.

The present invention contemplates a machine for the rapid andcontinuous production of fiber board of the highest quality, evenness,and strength, having smooth surfaces, of uniform thickness throughoutand having no tendency to split along its neutral axis when subjected tofiexing strains, During and immediately after formation. the board iscaused to travel through the machine in a plane which is preferablyhorizontal, and the unfinished board is not subjected to fiexuie which,as has been heretofore pointed out, has a weakening tendency. Uniformityof the board in internal structure and thickness is ensured by causingthe fibrous particles to be deposited rapidly and evenly on a fiatforming surface, the rapidity of fiber deposition being promoted bymaintaining above this fiat forming surface a body of pulp stock havinga high static head. The use of suction boxes for facilitating rapiddeposition of the fibers is dispensed with. I preferably employ, inconjunction with, the forming wire, a second or top wire which serves toconfine the formed board securely between itself and the forming wirewhile it is being passed through a series of rollers or other moistureextracting and board compressing devices.

The pulp stock chamber positioned above the forming wire is so designedand constructed that the fibers fall substantially vertically onto theforming surface throughout the entire extent of the forming area and insuch manner that they interlock or interlace with each other to amaximum extent, thus promoting perfection of internal formation of theboard and maximum strength of the resulting product. This pulp stockretaining chamber is also so designed that the density of concentrationof the fibrous material in the liquid is substantially the samethroughout its entire volume, there being no quiet volumes of liquidstock at any point there in from which the stock may be precipitatedonto the forming surface, leaving behind liquid substantially free ofstock.

The invention may be embodied in board forming machines which varywidely in appearance and in details of design and construction, as willbe apparent to one skilled in the art. By way of example, one embodimentof the invention is illustrated in the accompanying drawing and will behereinafter described in detail. In adapting the principles of theinvention to the manufacture of boards of various types and from fibersof different densities, lengths, and shapes, the design and arrangementof the component elements of the invention may be considerably modified.

The drawing illustrates, rather diagrammatically, in longitudinalvertical section, an embodiment of the invention which has been foundeminently satisfactory in practice. The frame of the machine isindicated generally at 10, this frame having suitable horizontal membersand preferably having legs 12, by means of which it is supported abovethe floor foundation. Rotatably mounted on the frame at one end thereofis a breast roll 13 and at the other end a bottom the rotatable tablerolls 15 and the lower rolls 16. 16 of two primary presses, the upperrolls of which presses are indicated at 1'7, 17.

An endless forming wire 18 passes over breast roll 13, table rolls 15,the lower rolls 16, 16 of the primary press rolls, and the bottom pressroll 14, these severalrolls just mentioned guiding that portion of theforming wire which at the time constitutes the upper reach thereof sothat it passes in a horizontal plane through the machine, the lowerreach of forming wire 18 being guided in its return movement by theguide and stretch rolls 19. The bottom press roll 14 is driven by asuitable driving mechanism, not illustrated, and in turn causes theforming wire 18 to move in an endless path in the direction of the arrowA.

Also mounted on the frame is a suitable pulp stock retaining chamber 20which projects upwardly to a considerable height above the forming wire.The pulp stock is conducted to this chamber in any suitable manner, asfor instance through the pulp'stock supply conduit 21. The pulp stockchamber 20 is provided with a suitable means for controlling the levelof its upper surface, that is, for controlling the head of pulp stock onthe forming wire 18.

In the embodiment of the invention illustrated, several apertures in thewall of the pulp stock chamber are provided, one above the other, andmanually controllable gates 22 so mounted on the wall of the pulp stockchamber as to be movable to open or close these openings. The pulp stockwill rise in chamber 20 until it reaches the first uncovered opening andwill overflow at that point so that the height of the liquid may becontrolled at the will of the operator. In the operation of the machine,the pulp stock is caused to flow into the chamber at a rate faster thanit can be handled by the forming wire so that there is always acontinuous overflow through that port which is at the time constitutingan overflow port. The height of the body of pulp stock in the chambercan, therefore, always be regulated at will.

The forming wire is driven at a uniform rate of speed by the bottompress roll 14 or other mechanism, and the pulp stock, which is indicatedat 23, is maintained at a constant level upon the upper surface of theforming wire by the pulp stock chamber 20 so that the static pressure ofthe stock at the forming surface remains constant. The upper reach ofthe forming wire 18, at least a portion thereof, constitutes in realitya foraminous closure for the otherwise open bottom of chamber 20, and inthe operation of the machine, the liquid of the pulp stock rapidlydrains through the forming wire, and the fibers thereof are depositedupon the forming wire.

As any given section of the forming wire passes beneath chamber 20, thedeposit of fibers thereon gradually increases, and the board, still in avery soft state, finally makes its escape from chamber 20 by passing,together with the forming wire, beneath the lower horizontal edge of aninclined member 24 which in reality comprises a movable wall of the pulpstock chamber 20, member 24 being hinged at 25 to one stationary wall ofthe chamber. The inclined and pivotally mounted member 24 comprisesessentially two spaced elements or plates 26 and 2'7, the athacentparallel edges of which are slightly spaced to provide a gap 28 for thepassage of a top wire, hereinafter to be more fully described,

press roll 14. Intermediate these two rolls are,

The top wire of the machine is indicated at 30, and this top wire isintended to contact with the upper surface of the freshly formed boardand to confine the fibrous material of the board between itself and theforming wire while the board is passing between pressure rollers. Aseries of pressure rollers of relatively small diameter is indicated at31, these rollers having their ends rotatably mounted in suitablebrackets depending from spaced horizontal and longitudinally extendingbars 32, which .bars are pivotally connected to free ends of member 24.

The top wire 30 enters the pulp stock chamber 20 through slot 28' and,after passing beneath plate element 27, contacts with the upper surfaceof the board freshly formed upon the forming wire and makes its escapefrom the pulp stock chamber beneath the forward edge of plate =27. Thisedge, and indeed the entire member 24, may oscillate slightly about theaxis 25 to accommodate slight variations in board thickness, but followsthe upper surface of the board so accurately that the free pulp stockcannot make its escape from the pulp stock chamber. Thereafter, the topforming wire passes under pressure rollers 31 and upper rollers 17, 17of the primary presses, around top press roll 33, and is guided back tothe slot 28 by the upper guide and stretch rolls 34. After passingbeneath the pressure rolls 31, through the primary presses 17, andbetween the top and bottom press rolls 14 and 33, the board issufiiiciently strong to support its own weight' through additionalpresses or directly to a dryer as desired, preferably in a direct line,without bending.

In addition to the press rolls shown, additional rollers may be providedif thought necessary or desirable. The greater quantity of the liquid isremoved by the pressure means described, and the board issuing from themachine is, while damp, free of the great bulk of the moisture which itcontained at the point where it issued from the pulp stock chamber.

As will be seen from the drawing, the side bars 32 are hinged to themember 24 at 40, and suitable linkage 41 is pivotally mounted on theframe, as upon the lugs 42 integral with post 43.

therefore, is instrumental in maintaining the top wire and the free edgeof member 24 lightly pressed against the upper surface of the board asit emerges from the pulp stock chamber.

In the event that the board passing beneath the forward edge of member24 varies in thickness for any reason, member 24 will automaticallychange its position, either rising or falling as the case may be. As itis desirable that the pressure rolls 31 have, a similar capacity toadjust their positions for variations in board thickness, bars 32 areyieldably supported at their ends opposite pivot 40. In the presentinstance, lugs 50 are provided at the ends of these bars, to which arepivotally secured the lower ends of links 51, the upper ends of theselinks being in turn pivotally connected at 52 to weighted levers 53intermediate the ends thereof, one end of each of these levers beingpivoted, at 54, to the frame. By the action of the weighted lever 53,the rollers 31 Mounted beneath the upper reach of the forming wire andthe series of supporting and pressure rollers over which it passes is anelongated open-topped trough-like receptacle 55 having a drain opening56. Liquid falling from the forming wire or expressed from the formedboard falls into this trough-like member and may be returned by anysuitable conduit to be reused. Deflectors 57 are positioned to deflectliquid falling beyond the end of member 55 into the interior thereof.

The layer of fibers deposited upon the forming wire is indicated at 60,and it will be seen that the thickness of the board increases as theoutlet from the pulp stock chamber is approached. The rate of depositionof fibers on the forming wire, however, decreases as the thickness ofthe fiber layer increases due to the increased opposition of the thickerportions of the fiber layer to the passage of liquid.

In order to provide a pulp stock chamber in which the density ofconcentration of the fibrous material in the liquidis the samethroughout, that is, which has no quiescent areas free of fiber, andalso to provide an elongated pulp stock chamber covering a large area ofthe forming movement of stock toward the opposite end is at a uniformrate throughout the chamber, the chamber is formed with a portion havingwalls of considerable height to confine pulp under high static head anda forwardly extending portion which decreases in vertical transversecross-sectional area. Thus, that portion of the pulp stock chamberbeneath member 24; decreases in vertical transverse section toward itsforward or discharge end; that is, as the layer of fiber on the formingWire increases, the depth of liquid above the same decreases. I

By forming the chamber in the above manner the stock above each unitareaof the forming wire is maintained at about the -same density of fiberconcentration. Also the pulp stock slowly flows forwardly of the formingwire at the same rate over the entire area thereof, beneath the inclinedmember 24, the cross-section of the chamber decreasing as the rate offlow of liquid through the forming wire decreases. This novelconstruction of pulp stock chamber facilitates the formation of a fiberboard which is even, and homogeneous throughout and has high mechanicalstrength. The fibers in moving downwardly toward the formingsurface fallfreely in substantially vertical paths and, as a result, are.

caused to thoroughly interlock with each other, each fiber being engagedbyfa large number of others disposed at various angles thereto.

' The present application comprises a continuation of my copendingapplication Serial No. 328,095, filed December 24, 1928.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is z- 1. In a board making machine apulp stock chamber having an open bottom and an endless forming wire,the upper reach of which is "disposed substantially horizontally andconstitutes a moving foraminous closure for the bottom of said chamber,the said chamber being shaped to maintain a body of pulp stock on theupper surface of the wire and over the entire area of the wire which forthe time being constitutes the chamber bottom, the static pressure ofthe pulp stock at all points on this area of the wire being the same.

2. In a board making machine, incombination, a forming wire movable in agenerally horizontal direction in the continuous production of fiberboards, and a pulp stock chamber above the wire positioned and designedto maintain at all times a substantially quiescent body of pulp stock incontact with a predetermined area of the moving wire, said chamberhaving a portion which decreases in cross-sectional area in thedirection of movement of the forming wire.

3. In aboard making machine, in combination, a flat generally horizontalforming wire continuously movable in one direction, and an open-'bottomed pulp stock' chamber positioned above the same in such mannerthat the wire comprises a moving foraminous closure for the chambervbottom, the chamber having a portion extending in the direction ofmovement of the wire with parallel sides and downwardly and outwardlyinclined top terminating in close proximity to the forming wire. V I

4: The combination set forth in claim 3 in which the said top ishingedly mounted to oscillate about a horizontal axis-adjacent its upperedge. v

5. In a board making machine, in combination, a flat generallyhorizontal forming wire continuously movable in one direction, anopen-bottomed pulp stock chamber positioned above the same in suchmanner that the wire comprises a moving foraminous closure for thebottom of the chamber, and means for continuously feeding stock to saidchamber and maintaining a substantially constant static head therein,the chamber being designed to provide a large volume of stock over thoseportions of the forming wire where fiber deposition is rapid and arelatively small volume of stock directly over portions of the wireWhere fiber deposition is less rapid.

6. In a board making machine, in combination, a flat generallyhorizontal forming wire continuously movable in one direction, and meansfor maintaining above and in contact with a predetermined area of saidwire a body of pulp stock under substantially constant static pressure.whereby the fibers contained therein are caused t'o'be deposited on thewire, the fiber deposit on each transverse section of wire progressivelyincreasing as such section passes said means, said means being designedand constructed to provide a volume of stock directly above eachsuccessive section. of wire which decreases as the thickness of thefiber deposit thereon increases.

7. In a board making machine, the combination with a fiat horizontallytraveling forming wire and stationary means associated therewith forflowing onto each area of wire successively passing the same a quantityof pulp stock, the static pressure of which remains constant but thevolume of which, directly above each such area of wire, decreases as thethickness of the fiber layer depositedv thereon increases.

8. A board making machine comprising a straight forming wire and a pulpstock chamber adapted to maintain pulp stock under high static head onsaid wire, said chamber having a portion adapted to yieldingly pressagainst a board formed on said wire.

9. In a fiber board making machine, means for continuously collectingfibers from pulp stock and forming them into a board, which meansdelivers the board produced in a horizontal direction to press rolls,and a pulp stock chamber for maintaining a body of pulp stock under highstatic pressure vertically above the fiber collecting means.

10. In a fiber board making machine, an endless forming wire and a pulpstock chamber arranged over the wire and maintaining a body of pulpstock under high static pressure thereon, said box having a movable partdefining an adjustable opening through which the collected pulp iscontinuously passed outwardly from the forming area.

11. In a fiberboard making machine, an endless forming wire and a pulpstock chamber arranged over the wire and maintaining a body of pulpstock under high static pressure thereon,

said chamber having a movable part forming an opening through which thepulp is continuously passed outwardly from the forming area and pressrolls for pressing the formed stock.

12. In a board making machine, a frame, a pulp stock chamber mounted onsaid frame and having an adjustable overflow thereon and an open bottomdefining a forming area, a member mounted on said head box for yieldingmovement, a forming wire rotatably mounted on said frame 'and passingadjacent said open bottom, and -a second wire mounted above said formingwire for coaction therewith to press the formed stock passing out withthe forming wire from the forming area. r

13. In a board making machine having a pulp stock chamber in whicha'high static head may be maintained and a straight forming wire, apivotally mounted member for yieldingly pressing against the board onthe wire.

14. In a board making machine having a pulp stock chamber in which ahigh static head may be maintained and a forming wire, a pivotallymounted member yieldingly pressing against the board on the wire.

15. In a board making machine, a frame, a pulp stock chamber in which ahigh static head may be maintained mounted on said frame and having anadjustable overflow thereon and an open bottom defining a forming area,a member mounted onsaid head box for yielding movement,

said member being comprised of two imperforate elements placed end toend, a straight forming v wire rotatably mounted on said frame, saidwire passing adjacent said outlet to receive pulp therefrom, and asecondwire mounted above said forming wire, said second wire passingbetween said two elements.

16. A yieldingly mounted member for a board making machine employing awire, comprising two plate elements mounted end to end, the whole beingpivotally mounted at one end to a portion of the machine, the other endresting on the pulp formed on the wire and assisting in de-. fining aforming area.

17. A yieldingly mounted member for a board making machine employing aforming wire, comprising a plate member pivotally mounted at one end toa portion of the machine, the other end yieldably pressing upon the pulpformed on the wire.

18. In a board making machine employing a yieldingly mounted member anda forming wire, means for adjusting said member comprising a system oflevers tending to normally yieldingly force the outer end of said memberagainst the formed stock.

19. In a board making machine employing a yieldingly mounted member anda forming wire, means for adjusting said member comprising a system oflevers by which one end of the member is forced downwardly, said memberand said levers being counterbalanced by a weight in such manner thatthe deflector is normally yieldingly urged against the formed stock onthe wire.

20. In a machine for making fiber board, and employing a forming wireand a top wire, a member pivotally mounted at one end to a portion ofthe frame of the machine, pressure rolls arranged above said wire andpivotally engaging the outer end of said member, and means for normallyyieldingly urging the adjacent ends of said member and said bars againstthe top wire, thus urging the said wire against the formed stock on theforming wire.

21. In a machine for making fiber board, and employing a forming wire, amember pivotally mounted at one end to a portion of the frame of themachine, and pressure rolls arranged above said wire and pivotallyengaging the outer end of said member.

22. In a machine for making board and employing a forming wire, a frame,a post on said frame, ears on said post, pressure means mounted forpressure against said wire, a lever pivoted in said ears and having acounterweight at the opposite end thereof, and a link connecting saidmeans with said lever intermediate its pivot point stock, said meanscomprising a top wire passing through adjacent sections of said membercontact with said formed stock.

24. In a. board making machine, a forming wire disposed and movablesubstantially horizontally into and a pulp stock chamber positionedabove the wire and adapted to maintain in contact therewith a relativelylarge body of pulp stock comprising a mixture of fiber and carrierliquid, the pulp stock adjacent the forming wire being under uniform andrelatively high static pressure, the

forming wire permitting ready passage etherethrough of the carrierliquid while intercepting and retaining the fibers to form a layer ormat,

and being adapted to conduct the mat thus formed from beneath saidchamber without bending the same when moved horizontally in onedirection.

25. In a machine for the continuous production of fiber board, anendless forming wire having one reach thereof disposed and movablesubstantially horizontally, and a pulp stock chamber positioned abovethe horizontal reach of said wire and adapted to maintain in contacttherewith a of fiber and carrier liquid, the pulp stock adjacent theforming wire being under uniform and relatively high static pressure,the forming wire permitting ready passage therethrough of thecarrier'liquid while intercepting and retaining the fibers to form alayer or mat, and being adapted to conduct the mat thus formed frombeneath large body of pulp stock comprising a mixture static pressure,the forming wire permitting ready passage therethrough of the carrierliquid while intercepting and retaining the fibers to form a layer ormat, and being adapted to conduct the mat thus formed from beneath saidchamber without bending the same when moved horizontally in onedirection, and means for continuously supplying said chamber with freshpulp stock at the rate necessary to maintain its static pressureconstant.

JACOB EDGE.

